The present invention relates generally to interface devices for allowing humans to interface with computer systems, and more particularly to computer systems and computer interface devices that provide force feedback to the user.
Computer systems are used extensively in many different industries to implement many applications, such as word processing, data management, simulations, games, and other tasks. These types of applications are very popular with the mass market of home consumers. A computer system typically displays a visual environment to a user on a display screen or other visual output device. Users can interact with the displayed environment to perform functions on the computer, play a game, experience a simulation or "virtual reality" environment, use a computer aided design (CAD) system, or otherwise influence events or images depicted on the screen. Such user interaction can be implemented through the use of a human-computer interface device, such as a joystick, mouse, trackball, stylus and tablet, "joypad" button controller, foot pedal, yoke hand grip, or the like, that is connected to the computer system controlling the displayed environment. The computer updates the environment in response to the user's manipulation of an object such as a joystick handle or mouse, and provides feedback to the user utilizing the display screen and, typically, audio speakers.
One visual environment that is particularly common is a graphical user interface (GUI). Information within GUI's are presented to users through purely visual and auditory means such as a video monitor and sound card to present images and sound effects which describe various graphical metaphors of the operating system. Common GUI's include the Windows.RTM. operating system from Microsoft Corporation and the System 7 operating system from Apple Computer, Inc. These interfaces allows a user to graphically select and manipulate functions of the operating system of the computer by using a mouse, trackball, joystick, or other input device. Other graphical computer environments are similar to GUI's. For example, graphical "pages" on the World Wide Web of the Internet communication network utilize features similar to that of GUI's to select and operate particular functions. Some CAD systems similarly provide graphical presentations. In addition, there has been some contemplation of three dimensional (3-D) GUI's that present simulated 3-D environments on a 2-D screen.
GUI's typically require users to carefully move and position a user-controlled graphical object, such as a cursor or pointer, across the screen and onto other displayed graphical objects or predefined regions on a computer screen. Such manual tasks can be described as "targeting" activities where a user physically manipulates a mouse, joystick, or other interface device in order to command the cursor to a desired location or displayed object, known as a "target" herein. Such targets can include, for example, icons for executing application programs and manipulating files; windows for displaying icons and other information; pull-down menus for selecting particular functions of the operating system or an application program; buttons for selecting presented options; and scroll bars or "sliders" for scrolling information in windows.
Upon moving the cursor to the desired target, the user must maintain the cursor at the acquired target while pressing a button, squeezing a trigger, depressing a pedal, or making some other gesture to command the execution of the given selection or operation. Examples of targeting tasks include positioning a cursor on a graphical icon, selecting and pressing a graphical representation of a button, choosing among numerous items within a graphical representation of a pull-down menu, setting a continuous analog value from a provided range of values by positioning an indicator within a graphical representation of a scroll bar, selecting a region of text by highlighting a region using the cursor, as well as a number of other common windows-based and text-based metaphors.
The movement of a cursor onto various displayed graphical objects of a GUI may require significant dexterity. Users may move the cursor too far over an object and have to backtrack their cursor. Or, particular graphical objects might be mistakenly selected when the user does not wish to select the object due to pressing a button or moving the cursor by accident. In addition, a user may become confused as to which window a cursor is positioned in if the user is viewing other data on the screen at the same time as moving the cursor.
In particular, persons with neuromotor disabilities who suffer from spastic manual control have much greater difficulty interacting with GUI's because they lack the fine motor coordination required to manually position the computer cursor accurately and efficiently. While manual targeting activities are adequately executed by persons with normal neuromotor functionality, persons with spastic hand motions find such tasks to be physically challenging if not impossible.
What is needed is a computer system and interface device that will allow all users to more accurately and efficiently perform cursor movement activities and manipulate operating system and other functions within a GUI.